Technical Field
The present invention relates to a refrigerated storage unit.
Related Art
A food product such as seafood, produce (vegetable and fruit), meat and the like can easily lose their freshness, but it is necessary to maintain the freshness for a relatively long period of time from the time of harvesting or the like to distribution and displaying in a store. Moreover, such a food product is more preferred by a customer when the freshness is higher, and therefore the food product needs to be displayed in the store with the freshness maintained.
Conventionally, attempts have been made to maintain the freshness of the food product by using a freezer or the like to freeze or refrigerate the food product (for example, see patent document 1). However, when the food product is frozen, a cell membrane of the food product is destroyed, resulting in a problem of a decrease in flavor of the food product. Furthermore, the freezer, a refrigerator and the like (a refrigerated storage unit) perform temperature management by turning the power to a compressor ON or OFF or through inverter control. For this reason, a range of temperature error and temperature differences among locations within the refrigerated storage unit are large, and thus a problem has existed of not being able to perform a precise temperature adjustment. Therefore, if the refrigerated storage unit is regulated to a temperature at which freezing does not occur, in some cases the temperature may become relatively high, and it has been difficult to sufficiently maintain the freshness. Furthermore, temperature unevenness at each location within the refrigerated storage unit often occurs depending on a location where the food product is provided, a method of providing the food product, and the like. For this reason, another problem has existed that a temperature of one location becomes much higher than a set temperature, while a temperature of another location becomes much lower than the set temperature.
In particular, if the food product is transported while refrigerating it with the refrigerated storage unit installed on a truck pallet, or if the food product is transported while refrigerating it using a container with a refrigeration system loaded on a ship, cold air is not uniformly distributed within the refrigerated storage unit depending on a position and the like of the food product within the refrigerated storage unit. Thus, a problem that cooling unevenness occurs within the refrigerated storage unit has existed. In the summertime particularly, a temperature of a location where the cold air does not reach can becomes 20° C. or higher, and this can damage the food product.
The Patent Document 1 is JP-A 2010-43763